Electrolyte and lithium ion battery containing same

Abstract

The invention relates to the technical field of a lithium ion battery, in particular to an electrolyte and a lithium ion battery containing the same. The electrolyte disclosed by the invention comprises a lithium salt, an organic solvent and an additive, wherein the additive contains a bipolyester compound and a sulphate compound, the bipolyester compound comprises a carbonic bipolymer, a carboxylic biopolymer and a sultone biopolymer, and the sulphate compound comprises an annular sulphate compound and a straight-chain or branch-chain sulphate compound. The bipolyester compound can be used for effectively forming a film at a positive electrode and preventing an electrolyte from being oxidized at the positive electrode, so that the high-temperature performance and the cycle performance of the battery are effectively improved; and the sulphate compound can be used for preventing the bipolyester compound from being reduced at a negative electrode, so that the battery acquire favorable low-temperature charge-discharge performance and rate performance, and the cycle performance of the battery can also be improved.

Description

technical field [0001] The present application relates to the technical field of lithium-ion batteries, in particular, to an electrolyte and a lithium-ion battery containing the electrolyte. Background technique [0002] Lithium-ion batteries have significant advantages such as high specific energy, high specific power, long cycle life, and low self-discharge, and have been widely used in electronic products such as mobile communications, digital cameras, and video cameras. It is precisely because lithium-ion batteries have the above-mentioned remarkable advantages that lithium-ion batteries have become a hot spot in the development of energy storage and power batteries. However, with the wide application of lithium-ion batteries, higher requirements are put forward for the environmental adaptability of lithium-ion batteries, so that lithium-ion batteries are used in various environments; in addition, as lithium-ion batteries become smaller With the development of moderniza...

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Problems solved by technology

However, the above-mentioned schemes will lead to a series of problems such as poor electrochemical performance of lithium-ion batteries, such as high-temperature storage performance, low-temperature charge-discharge performance, and cycle life.

[0004] According to the patent report, the technology of improving the chain carbonate dimer, chain carboxylate dimer, chain sulfonate dimer or phosphate ester can improve the high temperature storage performance and cycle performance of the battery, but With higher and higher energy density, it is difficult to guarantee good low-temperature charge and discharge and rate performance of the battery only by the above.

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